<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
 <head>
  <meta http-equiv="content-type" content="text/html; charset=UTF-8">
  <title>Calculate a unique identifier for the contained objects</title>
<link media="all" rel="stylesheet" type="text/css" href="styles/03e73060321a0a848018724a6c83de7f-theme-base.css" />
<link media="all" rel="stylesheet" type="text/css" href="styles/03e73060321a0a848018724a6c83de7f-theme-medium.css" />

 </head>
 <body class="docs"><div class="navbar navbar-fixed-top">
  <div class="navbar-inner clearfix">
    <ul class="nav" style="width: 100%">
      <li style="float: left;"><a href="splobjectstorage.detach.html">« SplObjectStorage::detach</a></li>
      <li style="float: right;"><a href="splobjectstorage.getinfo.html">SplObjectStorage::getInfo »</a></li>
    </ul>
  </div>
</div>
<div id="breadcrumbs" class="clearfix">
  <ul class="breadcrumbs-container">
    <li><a href="index.html">PHP Manual</a></li>
    <li><a href="class.splobjectstorage.html">SplObjectStorage</a></li>
    <li>Calculate a unique identifier for the contained objects</li>
  </ul>
</div>
<div id="layout">
  <div id="layout-content"><div id="splobjectstorage.gethash" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">SplObjectStorage::getHash</h1>
  <p class="verinfo">(PHP 5 &gt;= 5.4.0, PHP 7, PHP 8)</p><p class="refpurpose"><span class="refname">SplObjectStorage::getHash</span> &mdash; <span class="dc-title">
   Calculate a unique identifier for the contained objects
  </span></p>

 </div>

 <div class="refsect1 description" id="refsect1-splobjectstorage.gethash-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="modifier">public</span> <span class="methodname"><strong>SplObjectStorage::getHash</strong></span>(<span class="methodparam"><span class="type">object</span> <code class="parameter">$object</code></span>): <span class="type">string</span></div>

  <p class="para rdfs-comment">
   This method calculates an identifier for the objects added to an
   <span class="classname"><a href="class.splobjectstorage.html" class="classname">SplObjectStorage</a></span> object.
  </p>
  <p class="para">
   The implementation in <span class="classname"><a href="class.splobjectstorage.html" class="classname">SplObjectStorage</a></span> returns
   the same value as <span class="function"><a href="function.spl-object-hash.html" class="function">spl_object_hash()</a></span>.
  </p>
  <p class="para">
   The storage object will never contain more than one object with the same identifier.
   As such, it can be used to implement a set (a collection of unique values)
   where the quality of an object being unique is determined by the value
   returned by this function being unique.
  </p>

 </div>


 <div class="refsect1 parameters" id="refsect1-splobjectstorage.gethash-parameters">
  <h3 class="title">参数</h3>
  <dl>
   
    <dt>
<code class="parameter">object</code></dt>

    <dd>

     <p class="para">
      The object whose identifier is to be calculated.
     </p>
    </dd>

   
  </dl>

 </div>


 <div class="refsect1 returnvalues" id="refsect1-splobjectstorage.gethash-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   A <span class="type">string</span> with the calculated identifier.
  </p>
 </div>


 <div class="refsect1 errors" id="refsect1-splobjectstorage.gethash-errors">
  <h3 class="title">错误／异常</h3>
  <p class="para">
   A <span class="classname"><a href="class.runtimeexception.html" class="classname">RuntimeException</a></span> is thrown when the returned
   value is not a <span class="type">string</span>.
  </p>
 </div>


 <div class="refsect1 examples" id="refsect1-splobjectstorage.gethash-examples">
  <h3 class="title">范例</h3>
  <p class="para">
   <div class="example" id="example-3560">
    <p><strong>示例 #1 <span class="function"><strong>SplObjectStorage::getHash()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">class&nbsp;</span><span style="color: #0000BB">OneSpecimenPerClassStorage&nbsp;</span><span style="color: #007700">extends&nbsp;</span><span style="color: #0000BB">SplObjectStorage&nbsp;</span><span style="color: #007700">{<br />&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;function&nbsp;</span><span style="color: #0000BB">getHash</span><span style="color: #007700">(</span><span style="color: #0000BB">$o</span><span style="color: #007700">)&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;</span><span style="color: #0000BB">get_class</span><span style="color: #007700">(</span><span style="color: #0000BB">$o</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;&nbsp;}<br />}<br />class&nbsp;</span><span style="color: #0000BB">A&nbsp;</span><span style="color: #007700">{}<br /><br /></span><span style="color: #0000BB">$s&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">OneSpecimenPerClassStorage</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$o1&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">stdClass</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$o2&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">stdClass</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$o3&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">A</span><span style="color: #007700">;<br /><br /></span><span style="color: #0000BB">$s</span><span style="color: #007700">[</span><span style="color: #0000BB">$o1</span><span style="color: #007700">]&nbsp;=&nbsp;</span><span style="color: #0000BB">1</span><span style="color: #007700">;<br /></span><span style="color: #FF8000">//$o2&nbsp;is&nbsp;considered&nbsp;equal&nbsp;to&nbsp;$o1&nbsp;so&nbsp;the&nbsp;value&nbsp;is&nbsp;replaced<br /></span><span style="color: #0000BB">$s</span><span style="color: #007700">[</span><span style="color: #0000BB">$o2</span><span style="color: #007700">]&nbsp;=&nbsp;</span><span style="color: #0000BB">2</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$s</span><span style="color: #007700">[</span><span style="color: #0000BB">$o3</span><span style="color: #007700">]&nbsp;=&nbsp;</span><span style="color: #0000BB">3</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">//these&nbsp;are&nbsp;considered&nbsp;equal&nbsp;to&nbsp;the&nbsp;objects&nbsp;before<br />//so&nbsp;they&nbsp;can&nbsp;be&nbsp;used&nbsp;to&nbsp;access&nbsp;the&nbsp;values&nbsp;stored&nbsp;under&nbsp;them<br /></span><span style="color: #0000BB">$p1&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">stdClass</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$p2&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">A</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #0000BB">$s</span><span style="color: #007700">[</span><span style="color: #0000BB">$p1</span><span style="color: #007700">],&nbsp;</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #0000BB">$s</span><span style="color: #007700">[</span><span style="color: #0000BB">$p2</span><span style="color: #007700">],&nbsp;</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
    </div>

    <div class="example-contents"><p>以上例程的输出类似于：</p></div>
    <div class="example-contents screen">
<div class="cdata"><pre>
2
3
</pre></div>
    </div>
   </div>
  </p>
 </div>


 <div class="refsect1 seealso" id="refsect1-splobjectstorage.gethash-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="function.spl-object-hash.html" class="function" rel="rdfs-seeAlso">spl_object_hash()</a> - 返回指定对象的 hash id</span></li>
   </ul>
  </p>
 </div>


</div></div></div></body></html>